====== Reading Controllers ======

Reading controllers on the GameTank requires to add ''#include "input.h"'' as an include file. The API is pretty straighforward:

  update_inputs();
  if (player1_buttons & INPUT_MASK_LEFT) {
    ...
  } else if (player1_buttons & INPUT_MASK_RIGHT) {
    ...
  }
  if (player1_buttons & INPUT_MASK_UP) {
    ...
  } else if (player1_buttons & INPUT_MASK_DOWN) {
    ...
  }
  // players_old_buttons is used to make sure users press and release the button
  if (player1_buttons & ~player1_old_buttons & INPUT_MASK_A) {
     ...
  }

===== Testing in the Emulator =====

  * The first controller is using the arrow key for directions and ZXC for the buttons
  * The second controller is using TFGH for directions and Tab QW for the buttons